Here's a website with some chord forms for irish mandolin. It says bouzouki, but the tuning (GDAE) is the sameas mandolin...
scroll down to neutral chords
neutral chords are those without the 3rd--so they are neither/both major and minor in feel.

Some of my favorite chord positions for Irish, are
775x (D)
x775 (G)
x553 (C)
775x or7750 (A)
Remember, these are neither major nor minor because they lack the 3rd, so they fit either.
0220 (Em)

Rich McCarthy